Wheel steering device

Abstract

To provide a wheel steering device with a simple configuration, capable of suppressing increases in manufacturing costs and weight, suppressing pressure on installation space in a vehicle body, and easily adjusting the direction of wheels. [Solution] A wheel steering device 100 having a steering unit 110 and a control unit, wherein the steering unit 110 has a main body 111, a steering transmission member 112 that rotatably connects the wheel T1 and the main body 111, and a steering mechanism 113, wherein the steering mechanism 113 has a transmission linear body 114, a transmission rotating body 115 that comes into contact with the transmission linear body 114 and operates it to move forward and backward, and a drive source 116 that is connected to the transmission rotating body 115 so as to be able to rotate forward and backward, wherein the steering transmission member 112 is provided with a transmission connection shaft 120, one end of the transmission linear body 114 is connected to the transmission connection part 112d via the transmission connection shaft 120, the drive source 116 is connected to the main body 111, and the control unit is configured to be able to control the rotation of the transmission rotating body 115.

Description

[Technical Field]

[0001] The present invention relates to a wheel steering device having a steering unit provided between a vehicle body and wheels for steering the wheels, and a control unit. [Background technology]

[0002] BACKGROUND ART Conventionally, as a wheel steering device for steering the wheels of an automobile or the like, for example, a wheel steering device (steering device 6) of a steering system described in Patent Document 1 is known.

[0003] The wheel steering device (steering device 6) known from Patent Document 1 drives an actuator 7 based on an output signal read by a sensor that indicates the operation of the steering wheel 2 of the steering device 3, and moves a rack gear meshed with a pinion rotated by the actuator 7 left and right, thereby changing the direction of a pair of left and right steered wheels 5 connected via tie rods 8 connected to the left and right ends of the rack gear, thereby enabling steering. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2023-104296 Summary of the Invention [Problem to be solved by the invention]

[0005] However, there is still room for improvement in the wheel steering devices known from the above patent documents and the like.

[0006] In other words, in the wheel steering device known from Patent Document 1 and the like, the left and right steered wheels change direction in tandem with the movement of the rack gear connected via a tie rod, so if a problem occurs with the balance of the directions of the left and right steered wheels, it may be difficult to easily adjust the directions of the left and right steered wheels. Furthermore, since the rack gear needs to be positioned between the left and right steering wheels across the vehicle body, the space required to install the steering device becomes large, which may result in severe constraints when securing space to place components other than the steering device. In particular, when shocks to the left and right steering wheels are individually absorbed by connecting a suspension to each wheel to absorb shocks during driving, the structure connecting the left and right steering wheels itself becomes complicated, which could increase costs and weight, and could complicate the layout of the surrounding parts inside the vehicle, including the wheel steering device.

[0007] Furthermore, the components constituting the steering device may become larger, which may increase manufacturing costs and weight.

[0008] The present invention aims to solve these problems by providing a wheel steering device with a simple configuration, which can suppress increases in manufacturing costs and weight, suppresses pressure on installation space within the vehicle body, and allows for easy adjustment of the direction of the wheels. [Means for solving the problem]

[0009] The wheel steering device of the present invention is an invention of a wheel steering device having a steering unit that is provided between a vehicle body and a wheel and steers the wheel, and a control unit, wherein the steering unit has a main body that is connected to the vehicle body, a steering transmission member that connects the wheel and the main body so that they can rotate relative to each other via a steering shaft, and a steering mechanism that steers the steering transmission member, and the steering mechanism has a transmission linear body that transmits steering force to the steering transmission member, a transmission rotor that comes into contact with the transmission linear body and operates it to move forward and backward, and a drive source that connects the transmission rotor to be rotatable in both forward and reverse directions around a transmission rotation axis that is the rotation axis of the transmission rotor, and the steering transmission member is provided with a transmission connection part that is arranged at a position that avoids the steering shaft, and the transmission connection part is rotatably connected to the transmission linear body around the transmission connection axis, and the drive source is rotatably connected to the main body, and the control unit is configured to be able to control the rotation of the transmission rotor by the drive source. The main body is swingably connected to the vehicle body via a swing shaft, and the steering transmission member is connected to the vehicle body via a buffer member.By doing so, the above-mentioned problems are solved. [Effects of the Invention]

[0010] In the wheel steering device of the invention of claim 1, the steering mechanism has a transmission linear body, a transmission rotating body that comes into contact with the transmission linear body and moves it forward and backward, and a drive source that connects the transmission rotating body so that it can rotate forward and backward around the transmission rotating axis, and the steering transmission member is provided with a transmission connection part that is positioned away from the steering axis, and the transmission connection part is rotatably connected to the transmission linear body around the transmission connection axis, the drive source is rotatably connected to the main body part, and the control part is configured to be able to control the rotation of the transmission rotating body by the drive source, so that by rotating the transmission rotating body forward and backward to move the transmission linear body forward and backward, the steering transmission member can be rotated around the steering axis, and thereby the direction of the wheel connected to the steering transmission member can be changed. Furthermore, because one steering unit steers one wheel, even when steering a pair of left and right wheels like in an automobile, it is only necessary to place an independent steering unit for each wheel, so the steering unit can be installed by simply securing space around the wheels.Therefore, there is no need to use large components to connect the pair of left and right wheels, it does not take up much space inside the vehicle body, and the device configuration and layout with surrounding parts inside the vehicle body do not become complicated. Furthermore, there is no need for a large component that crosses the vehicle body between the pair of left and right wheels, and the steering unit can be constructed inexpensively. Furthermore, since the wheels are steered together with the steering transmission member by moving the transmission linear body back and forth, the steering unit configuration itself does not move significantly, and the configuration can be designed to be more compact and simple than a configuration in which the left and right steering wheels are connected via a tie rod or the like. Furthermore, since the main body is connected to the vehicle body via a swing axis so that it can swing, and the steering transmission member is connected to the vehicle body via a buffer member, even on uneven roads or when there are obstacles that can be overcome, the wheels can swing around the swing axis together with the steering unit, and the momentum during swinging can be reduced by the buffer member, thereby maintaining stable driving.

[0011] According to the configuration described in claim 2, the transmitting linear body is composed of a pin rack and the transmitting rotating body is composed of a pin gear, so that the error in the steering angle relative to the amount of rotation of the transmitting rotating body is only small within the range of meshing between the pin rack and the pin gear, and stable steering can be maintained for a long period of time. Furthermore, pin racks do not require as high a machining precision as rack gears, which helps to reduce manufacturing costs, and they also do not require as high an installation precision as rack gears, which means that precision control during installation is not complicated. Furthermore, when the pin rack or pin gear becomes worn, it can be replaced with a pin rack or pin gear of the same standard, allowing for easy and stable wheel steering without the need for major adjustments.

[0012] Claim 3 According to the configuration described above, the control unit is configured to be able to control the rotation of the transmission rotor by the drive source based on an operation signal from the operating unit of the vehicle body, so that, for example, when a driver in the vehicle operates a steering wheel provided on the operating unit, the control unit receives an operation signal from the operating unit corresponding to the amount of operation of the steering wheel, and can drive the drive source to steer the wheels so that the steering angle of the wheels corresponds to the amount of operation of the steering wheel. Claim 4 According to the configuration described above, a pair of left and right wheels are provided on the vehicle body, one steering unit is provided for each of the multiple wheels to be steered, and the control unit is configured to be able to control the multiple steering units simultaneously, so that the control unit can steer the pair of left and right steering units in conjunction with each other, and the steering angle of one of the pair of left and right wheels can be easily adjusted individually without affecting the other of the pair of left and right wheels.

[0013] Claim 5 According to the configuration described above, the steering unit further has a detection unit capable of detecting the steering angle of the steering transmission member, and the control unit is configured to be able to control the rotation of the transmission rotor by the drive source based on information about the steering angle of the steering transmission member detected by the detection unit.Therefore, even if a discrepancy occurs between the steering angle specified by the control unit and the actual steering angle of the wheels, the control unit can automatically correct the discrepancy in the steering angle by comparing the information about the actual steering angle from the detection unit with the steering angle specified by the control unit, thereby maintaining even more stable and accurate steering. [Brief explanation of the drawings]

[0014] [Figure 1]1 is a schematic top view showing a vehicle P equipped with a wheel steering device 100 according to an embodiment of the present invention. [Figure 2] 1 is a top view of a wheel steering device 100 according to an embodiment of the present invention. [Figure 3] 1 is a front view of a wheel steering device 100 according to an embodiment of the present invention. [Figure 4] 1 is a side cross-sectional view of a wheel steering device 100 according to an embodiment of the present invention. [Figure 5] 1 is a top view showing a state in which a front wheel T1 is steered by a wheel steering device 100 according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] A wheel steering device 100 according to one embodiment of the present invention will be described below with reference to the drawings. For the sake of explanation, the control unit is not shown.

[0016] A wheel steering device 100 according to one embodiment of the present invention is attached between a front wheel T1, which is a wheel of a traveling vehicle P, and a vehicle body F, as shown in FIGS. In addition, a configuration similar to the wheel steering device 100 is installed on the front wheel T2 side between the front wheel T2 and the vehicle body F, and is configured so that the front wheels T1 and T2 can be steered in conjunction with each other by a common control unit. Furthermore, the rear wheels T3 and T4 are attached to the vehicle body F rotatably around the central axes of the rear wheels T3 and T4 without using a configuration similar to that of the wheel steering device 100.

[0017] The wheel steering device 100 according to one embodiment of the present invention has a steering unit 110 that is provided between the vehicle body F and the front wheels T1 and that steers the front wheels T1, and a control unit. The steering unit 110 has a main body 111 connected to the vehicle body F, a steering transmission member 112 that connects the front wheel T1 and the main body 111 so that they can rotate relative to each other via a steering shaft 123, and a steering mechanism 113 that steers the steering transmission member 112.

[0018] The steering mechanism 113 has a transmission linear body 114 having a pin rack 114a and one end connected to a transmission connection shaft 120 described later, a transmission rotating body 115 consisting of a pin gear that meshes with the pin rack 114a and moves the transmission linear body 114 forward and backward, and a drive source 116 that connects the transmission rotating body 115 so that it can rotate forward and backward around a transmission rotating shaft 116a as the center of rotation.

[0019] The steering transmission member 112 has an upper stage portion 112a, a lower stage portion 112b, and an intermediate connection portion 112c that connects the upper stage portion 112a and the lower stage portion 112b. The intermediate connection part 112c is rotatably connected to the front wheel T1 via a connection shaft 119.

[0020] The upper stage portion 112a has a transmission connection portion 112d that connects to the transmission connection shaft 120 at one end of the upper stage portion 112a along the rotation direction of the front wheel T1. The upper surface of the upper stage portion 112a is connected to the buffer member 121, and the lower stage portion 112b is connected to the main body portion 111 with the steering shaft 123 as the rotation axis. A steering angle detection unit S capable of detecting the actual steering angle of the steering transmission member 112 is provided between the main body 111 and the lower section 112b, and the steering angle detection unit S is configured to be able to transmit information on the detected actual steering angle of the steering transmission member 112 to the control unit.

[0021] The main body 111 is connected to the vehicle body F so as to be swingable around a swing shaft 118 as the swing center, and fixes the drive source 116 at a predetermined height via an interlocking fixing member 122 so as to be rotatable around an interlocking rotation shaft 124 as the rotation center. As a result, by simply changing the shape of the interlocking fixing member 122, the driving source 116 can be easily positioned so that the pin rack 114a and the transmission rotor 115 are optimally meshed with each other. In addition, spacers SP are sandwiched between the upper stage 112a and the transmitting linear body 114, and between the main body 111 and the interlocking fixing member 122, and the positional relationship in the height direction of each can be adjusted by changing the thickness of the spacers SP.

[0022] Next, a method for steering the front wheels T1 using the wheel steering device 100 according to one embodiment of the present invention will be described with reference to FIGS. In addition, a traveling vehicle P equipped with a wheel steering device 100 according to one embodiment of the present invention transmits an operation signal from an operating unit (not shown) to a control unit when the driver operates a steering unit (not shown).

[0023] First, a driver in the traveling vehicle P operates a steering unit (not shown) so that the traveling vehicle P makes a leftward turn. At this time, the operating unit (not shown) transmits an operation signal to the control unit that changes depending on the amount of operation of the steering unit (not shown) by the driver, and the control unit determines the target steering angle based on the received operation signal.

[0024] Based on the information on the determined target steering angle, the control unit controls the forward and reverse rotation of the drive source 116 to rotate the transmission rotor 115, and sends the pin rack 114a of the transmission linear body 114, which is meshed with the transmission rotor 115, toward the transmission connection shaft 120. As a result, the steering transmission member 112 receives a force pushing the transmission connection part 112d by the transmission linear body 114 through the transmission connection shaft 120, and rotates around the steering shaft 123 as the center of rotation until it reaches the target steering angle, and the front wheel T1 connected to the steering transmission member 112 also changes direction together with the steering transmission member 112 until it reaches the target steering angle.

[0025] At this time, the steering angle detection unit S is configured to be able to transmit information on the detected actual steering angle of the steering transmission member 112 to the control unit, so that the control unit can compare the target steering angle with the information on the actual steering angle of the steering transmission member 112 and adjust the rotation angle of the transmission rotor 115 via the drive source 116 so that the steering transmission member 112 reliably reaches the target steering angle. Furthermore, as the steering transmission member 112 is pushed by the linear transmission body 114 and rotates, the linear transmission body 114 also gradually moves to change its orientation relative to the rotating transmission body 115. However, since the main body 111 fixes the drive source 116 at a predetermined height via the interlocking fixing member 122 so that it can rotate around the interlocking rotation shaft 124 as the center of rotation, the transmission rotation body 115 can also change its orientation together with the drive source 116 around the interlocking rotation shaft 124 as the center of rotation so as to align the meshing direction with the pin rack 114a of the linear transmission body 114, thereby maintaining stable steering. In addition, there is almost no time lag between the operation of the steering unit (not shown) and the front wheel T1 starting to turn toward the target steering angle via the operating section (not shown) and the control section, so the driver can drive the moving vehicle P without any discomfort.

[0026] Furthermore, the control unit is configured to be able to steer the wheel steering device on the front wheel T2 side as well, so that the front wheels T1 and T2 can be steered in conjunction with each other by the driver operating a handle unit (not shown). Furthermore, if the control unit is configured to be able to detect information on road conditions, the speed, acceleration / deceleration, and cornering state of the traveling vehicle, the steering angle of the front wheels T1 and T2 can be individually adjusted in response to the operation of the handle unit (not shown) depending on the road conditions and the state of the traveling vehicle, and therefore the optimal direction of the front wheels T1 and T2 can be automatically selected depending on the traveling conditions.

[0027] As described above, the wheel steering device 100 according to one embodiment of the present invention can steer the front wheels T1 and T2 at optimal steering angles to change their direction in response to the driver's operation of the steering unit (not shown). In addition, one wheel steering device is provided for each of the front wheels T1 and T2 arranged side by side, and each wheel steering device is configured so that steering is adjusted by a control unit. Therefore, it is only necessary to secure installation space for the wheel steering device around each of the front wheels T1 and T2, and there is no need to use large components that connect the front wheels T1 and T2 to transmit power, so the space inside the vehicle body F is not taken up significantly.

[0028] Furthermore, since no large components are used to connect and transmit power between the front wheels T1 and T2, the manufacturing costs of the wheel steering device itself can be kept low, and the device can be made lighter in weight, improving the fuel efficiency of the traveling vehicle. Furthermore, since the front wheel T1 is steered together with the steering transmission member 112 by moving the transmission linear body 114 connected to the transmission connection shaft 120 back and forth, the configuration of the steering unit 110 itself does not move significantly, and the design can be more compact and simple than a configuration in which the left and right front wheels T1, T2 are connected via a tie rod or the like.

[0029] Furthermore, since the linear transmission body 114 has a pin rack 114a and the rotating transmission body 115 is composed of a pin gear, the error in the steering angle relative to the amount of rotation of the rotating transmission body 115 is only small and is within the range of meshing between the pin rack and the pin gear, making it possible to maintain stable steering for a long period of time. Furthermore, pin racks do not require as high a machining precision as rack gears, which helps to reduce manufacturing costs, and they also do not require as high an installation precision as rack gears, which means that precision control during installation is not complicated. Furthermore, when the pin rack or pin gear becomes worn, it can be replaced with a pin rack or pin gear of the same standard, allowing for easy and stable wheel steering without the need for major adjustments.

[0030] Furthermore, the main body 111 is connected to the vehicle body F via the swing shaft 118 so that it can swing, and the steering transmission member 112 is connected to the vehicle body F via the buffer member 121, so that even on a road with steps or an obstacle that can be overcome, the front wheel T1 can swing around the swing shaft 118 together with the steering unit 110, and the momentum during the swing can be reduced by the buffer member 121, thereby maintaining stable driving. Since the steering unit 110 swings in conjunction with the main body 111, the steering unit 110 can still perform its steering function even when swinging, allowing for even more stable driving to be maintained.

[0031] Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various design modifications can be made without departing from the present invention as set forth in the claims.

[0032] In the above-described embodiment, a wheel steering device is attached to each of the front wheels located on the left and right sides of the front of the vehicle body, but the location where the wheel steering device is attached and the configuration of the running vehicle are not limited to this. For example, the wheel steering device may be attached to the rear wheel, or the wheel steering device may be attached to the only front wheel located at the front of the vehicle body. Furthermore, in the above-described embodiment, the linear transmission body has a pin rack, and the rotating transmission body is configured with a pin gear, but the configuration of the linear transmission body and the rotating transmission body is not limited to this. For example, the surface of the linear transmission body may be provided with a rubber plate-like anti-slip plate, and the rotating transmission body may be configured with a roller that comes into contact with the rubber plate-like anti-slip plate and moves the linear transmission body back and forth by frictional force.

[0033] Furthermore, in the above-described embodiment, the control unit is described as receiving an operation signal transmitted from the operating unit when the driver operates the steering unit, and operating the drive source to steer the front wheels; however, the operation signal received by the control unit is not limited to this, and for example, the control unit may be configured to receive an operation signal transmitted automatically by the autonomous vehicle, rather than by the driver, and operate the drive source to steer the front wheels, or the control unit may be configured to be operated by the driver using a wireless controller that can communicate with the control unit, without a steering unit attached to the vehicle body. Furthermore, in the above-described embodiment, it has been described that spacers are provided between the steering transmission member and the transmission linear body and between the main body and the interlocking fixing member, but the connection relationship of each member is not limited to this, and for example, a spacer need not be provided. [Explanation of symbols]

[0034] 100 Wheel steering device 110 Steering unit 111 Main body 112 Steering transmission member 112a... Upper section 112b ... lower section 112c Intermediate joint 112d Transmission connection 113 Steering mechanism 114 ··· Linear transmission body 114a ··· Pin rack 115 Rotating transmission body 116 ··· Drive source 116a Transmission rotating shaft 118 ··· Oscillating shaft 119 Connecting shaft 120 Transmission connection shaft 121 ··· Cushioning material 122 Interlocking fixing member 123 Steering shaft 124 ··· Interlocking rotary shaft F... Body P... Vehicle in motion T1, T2 Front wheels T3, T4 Rear wheels S Steering angle detector SP ··· Spacer

Claims

1. The present invention relates to a wheel steering device having a steering unit that is provided between a vehicle body and a wheel and steers the wheel, and a control unit, The steering unit includes a main body connected to a vehicle body, a steering transmission member that connects a wheel and the main body via a steering shaft so as to be rotatable relative to each other, and a steering mechanism that steers the steering transmission member, the steering mechanism includes a linear transmission body that transmits a steering force to the steering transmission member, a transmission rotation body that contacts the linear transmission body and moves forward and backward, and a drive source that connects the transmission rotation body to a transmission rotation shaft that is a rotation shaft of the transmission rotation body and is rotatable in both forward and reverse directions around the rotation center, The steering transmission member is provided with a transmission connection portion that is arranged at a position that avoids the steering shaft, the transmission connection portion is rotatably connected to the transmission linear body around a transmission connection axis, the drive source is rotatably connected to the main body, the control unit is configured to be able to control the rotation of the transmission rotor by the drive source, The main body is swingably connected to a vehicle body via a swing shaft, A wheel steering device characterized in that the steering transmission member is connected to the vehicle body via a buffer member.

2. The transmission linear body is constituted by a pin rack, 2. The wheel steering device according to claim 1, wherein the transmission rotor is a pin gear.

3. 2. The wheel steering device according to claim 1, wherein the control unit is configured to be able to control the rotation of the transmission rotor by the drive source based on an operation signal from an operation unit on the vehicle body.

4. A pair of wheels is provided on the left and right sides of the vehicle body. the steering unit is provided for each of a plurality of wheels to be steered, 2. The wheel steering device according to claim 1, wherein the control unit is configured to be able to simultaneously control a plurality of the steering units.

5. the steering unit further includes a detection unit capable of detecting a steering angle of the steering transmission member, 2. The wheel steering device according to claim 1, wherein the control unit is configured to be able to control the rotation of the transmission rotor by the drive source based on information about the steering angle of the steering transmission member detected by the detection unit.

Images